Попробуйте передать имя пользователя и пароль, записанные в Android, в PHP для запроса базы данных MYSQL

Код запрашивает пользовательскую таблицу («имя»), чтобы получить китайское имя, соответствующее имени пользователя (уникальному), введенному пользователем.

В режиме DEBUG обнаружил, что имя пользователя в $ _POST [‘username’] пусто при передаче в PHP. Я могу получить китайское имя в режиме отладки. Пожалуйста, помогите выяснить, что не так в передаче параметров.

Android часть для отправки POST-запроса в PHP.

public class SigninActivity  extends AsyncTask<String,Void,String> {

private TextView statusField,roleField;
private Context context;
private int byGetOrPost = 0;
//flag 0 means get and 1 means post.(By default it is get.)
public SigninActivity(Context context,TextView statusField,
TextView roleField,int flag) {
this.context = context;
this.statusField = statusField;
this.roleField = roleField;
byGetOrPost = flag;
}

protected void onPreExecute(){

}
@Override
protected String doInBackground(String... arg0) {
if(byGetOrPost == 0){ //means by Get Method
try{
String username = (String)arg0[0];
String password = (String)arg0[1];
String link = "http://www.example.com/login.php?username="+username+"&password="+password;
URL url = new URL(link);
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(link));
HttpResponse response = client.execute(request);
BufferedReader in = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));

StringBuffer sb = new StringBuffer("");
String line="";
while ((line = in.readLine()) != null) {
sb.append(line);
break;
}
in.close();
return sb.toString();
}catch(Exception e){
return new String("Exception: " + e.getMessage());
}
}
else{
try{
String username = (String)arg0[0];
String password = (String)arg0[1];
String link="http://www.example.com/login.php";
String data  = URLEncoder.encode("username", "UTF-8")
+ "=" + URLEncoder.encode(username, "UTF-8");
data += "&" + URLEncoder.encode("password", "UTF-8")
+ "=" + URLEncoder.encode(password, "UTF-8");
URL url = new URL(link);
URLConnection conn = url.openConnection();
conn.setDoOutput(true);
OutputStreamWriter wr = new OutputStreamWriter
(conn.getOutputStream());
wr.write( data );
wr.flush();
BufferedReader reader = new BufferedReader
(new InputStreamReader(conn.getInputStream()));
StringBuilder sb = new StringBuilder();
String line = null;
// Read Server Response
while((line = reader.readLine()) != null)
{
sb.append(line);
break;
}
return sb.toString();
}catch(Exception e){
return new String("Exception: " + e.getMessage());
}
}
}
@Override
protected void onPostExecute(String result){
this.statusField.setText("Login Successful");
this.roleField.setText(result);
}
}// Code in PHP

$con = mysqli_connect($mysql_hostname, $mysql_user, $mysql_password) or     die("Could not connect database");if (mysqli_connect_errno($con))
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}mysqli_select_db($con, $mysql_database) or die("Could not select database");if (DEBUG) {
echo "Connected to database $mysql_database";
}mysqli_set_charset($con, 'utf8');

$username = mysqli_real_escape_string($con, $_POST['username']);
$password = mysqli_real_escape_string($con, $_POST['password']);

if (DEBUG) {
$username = "b";
}

$qry1 = "SELECT c_f_name FROM name where username = \"$username\" ";

$result = mysqli_query($con, $qry1);
if(DEBUG) {
echo "This is the username: ";
echo $username;

if ($result) {
echo $username;
//successful query
if (mysqli_num_rows($result) > 0) {
echo "query successful -
";
echo mysqli_num_rows($result);
} else {
echo "query successful-0 rows
";
}
} else {
// query not successful
echo "Query unsuccessful";
}

}

$row = mysqli_fetch_array($result);
//Since there is only 1 record that match, just retrieve the first and only record
$data = $row[0];
if($data){
echo $data;
}

mysqli_close($con);
?>